Safety device for mine shafts



Patented Aug. 17, 1926.

.UNITED s re-"fee earanr l OFFICE.

JAMES 1G. MARCUM, OF JOPALIN, MISSOURI, ASSIGIYOR.V OF ONE-HALF T0 FRANK CHILDRESS, OF JOILIN, MISSOURI.

SAFETY DEVICE FOR MINE SHAFTS.

AppIication filed n Octob This invention relates to for mine shafts.

safety devices It is well known that miners are often ei;-

pose'd to grave danger in mines having open shafts, as it often happens ore, rock into the mines thru the shafts.

various kinds are employed that lumps of or other solid substances fall downy fis lioists of in mines, these must pass thru the shafts which necessitates that the shafts shall be so constructed that automatically close after be opened wide eno-ugh to permit and down.

of this invention to pro at can be closed articles of any dethe surface into the time will open or bucket pass upwardly and q the cage has passed. I also provide means for opening the 'doors so as to permit the cage to move downwardly.

My invention can stood and most clearly erence is had to the accompa be most readily underdescribed whenrefnying drawing,

in which the preferred embodiment thereof is shown and in which Fig. 1 is a vertical section of a mine shaft,

taken on line 1-1, equipped with safety doors Fig. 2, showing the same constructed in accordance with my invention, and

Fig. 2 is a section of the saine shaft taken at right angles to that in Fig. 1 and along line 2-2, Fig. 1.

In the drawing, vention in its pre I have illustrated my inferred form. Numeral 10 designates a vertical shaft thru which a cage or skip travels. I

have not shown the hoist asthat is old and well known and forms no but h part of my invention,

device drawing to the safety by which it is operated.

ave limited the and the means The shaft is enlarged at a point located some distance beneath the surface of the ground. A rectangular frame comprising side pieces 12 is placed on end pieces 11 and the ledge which forms the bottom of the enlargement. Fivotally mounted at 111 and 15 are doors 16 and 17. steel, but have These doors may been shown from a steel frame and covered with a As will be noticed from Fig. 1, the wide that when they are in plate. doors are so closed position, they form be made of wood or as constructed steel a gable roof.

Vto descend after which they may be cl er' 3, 192e. seriai No. 741,519.

.passes around a pulley 25. Let us now assume that aforce of sufficient value is applied to the cable 18 to move the same upwardly. This will move the doors from the full line to the dotted line positions in Fig. 1 or to open position. Since the doors are uite massive and are mounted on pivots, 14 and 15, which oppose very little resistance to rotation, and since they are never opened to a vertical position, they always tend to close. If the tension in the cable 18 is released, tlie doors will immediately start closing, but the door 16 can close no faster than the door 17 on account of the cable 22. In order that the door 17 shall stop at the proper place and that it shall not pass beyond the point shown in full lines in Fig. 1, I have secured the same by means of a short length of cable 26 with one of my uprights 27. It is therefore vevident that the doors will always come together in the position shown in Fig.

'The cable 18 extends to the top of the ground and may be fastened to a hoisting drum or other means by which it may be manipulated for the purpose of opening and closing the doors.

^ If the shaft is employed for a hoist, the doors are opened to permit the cage or skip ose and remain closed until the cage' asc-ends, when the doors are opened to let it pass and are again closed as soon as the cage has passed thru. In this way the workmen in the mine are protected against injury from falling objects of all kinds.

It is, of course, evident that as many sets of doors may be provided as may be deemed necessary, as this requires only a duplication of the doors described. The location of the doors along the shaft is also a matter of choice. Some may desire to have them quite near the top'while others may be of dos the opinion that some other location is better. I therefore do not desire to be limited to any particular location.

l also wish to call attention to the fact that the operating cables may be extended to any and as many place or places as it may be found desirable to have the hoist operated from.

Having now described my invention, what I claim as new is:

A safety device for mine shafts comprising a vertical shaft having an enlargement7 a rectangular trame located in said enlarge` nient, said frame lying` in a substantially horizontal plane, the opening in said frame corresponding with the opening in the shaft,

a door hinged to each of the opposite side members oi said frame, each door being wider than one-half the distance between the axes about which the doors swing, means for preventing the doors from overlapping, means comprising a cable secured to one of said doors and passing about a pulley located above an'd to the rear of the door whereby when a pull is exerted on the cable the door will be moved about its pivot to open position and means connecting the doors which causes them to open andclose in unison when the cable is moved in one direction or the other. A

n testimony whereof I ami( my signature.

JAMES G. MARCUM. 

